11 DECEMBER THE NEW ZEALAND GAZETTE 3771

THE NEW ZEALAND WEATHER IN OCTOBER 1981

General—October was cool and dry for most of the North Island and milder and wetter than normal in the South Island.

There was a slightly higher incidence of strong winds than usual in the south of the country but winds were otherwise close to normal for October.

Extremely high north-westerly winds affected inland parts of the South Island from Te Anau to the McKenzie Basin during the 3rd and 4th. Severe damage to buildings was reported throughout the area and one person was killed by flying debris in Twizel. Plantations were extensively damaged. The following maximum gusts were recorded at anemometer sites in the area (previous or existing record gusts follow in parentheses):

Queenstown 70 kts (58 kts),
Aviemore 104 kts (117 kts),
Mt. John 113 kts (135 kts),
Lake Pukaki 62 kts (62 kts), and
Lauder 100 kts estimate—a new installation.

Farmers throughout the country report spring growth to be progressing well although cool night time temperatures and late frosts have retarded growth in some northern areas. Frosts during the last few days of the month damaged kiwifruit crops around Te Puke and walnut crops around Taumarunui. Hail on the 30th damaged some stonefruit crops around Christchurch.

Rainfall—The North Island had below normal rainfall in all areas except Gisborne, Bay of Plenty, Wairarapa, and Wellington. Parts of the Northland, Auckland, and Taupo districts had less than half their normal October rainfalls while the Wairarapa region had close to twice normal rainfall.

In the South Island rainfalls were mainly close to or above normal for October. A notably wet region was the area from Oamaru to Christchurch which had close to 200 percent of normal rainfall. Southern Westland and Central Otago had slightly less than normal rainfall.

Temperature—North Island temperatures were up to 1.0°C above normal in central and eastern areas and up to 1.0°C below normal in the north and south. The Nelson Lakes, inland Canterbury and Oamaru areas of the South Island had mean temperatures more than 1.0°C above normal while other areas were up to 1.0°C above normal.

There were several very warm spells during periods of north-westerly winds this month. During the period between the 1st and 4th maximum temperatures in eastern and south-eastern areas were above 20°C with Gisborne, Napier, Timaru, Christchurch, Oamaru, Dunedin, and Kaikoura recording temperatures above 25°C at times. Minimum temperatures were as much as 15°C above the average minimum for the month in some areas.

During the 7th and 8th temperatures in the same areas were again above 20°C, although minimum temperatures were not as high as those on the previous occasion.

Warm temperatures were recorded over most of the country during the 21st and 22nd when both maximum and minimum temperatures were 3–8°C above average.

There were two very cool periods, the first between the 17th and 18th and the second at the end of the month when severe late frosts were experienced in many parts of the country.

Sunshine—Sunshine totals were close to, or above normal for the month over most of the country. The North Island had above normal sunshine everywhere except in southern areas where sunshine totals were about 10 hours below average. In the South Island the Marlborough, Canterbury, and Otago areas had between 10 and 30 hours less sunshine than usual while all other areas were sunnier than average.

THE WEATHER SEQUENCE, OCTOBER 1981

1–7 October
An extensive anticyclone passed to the north of New Zealand during the first 4 days of October bringing fine weather to the North Island and northern South Island. At the same time there was a strong west or north-westerly flow over the south of the country and this brought rain to many parts of the South Island, particularly southern and western areas. A trough of low pressure crossed the country between the 5th and 7th. Rain fell over most of New Zealand on the 5th and in central and western districts on the 6th and 7th with the passage of frontal systems within this trough.

8–14 October
By the beginning of the second week in October the trough lay to the east of New Zealand and an anticyclone covered the North Island. A second trough formed in the south Tasman Sea and an associated north-westerly flow brought rain to western areas of the South Island. This trough crossed the country rapidly and by the 9th the anticyclone to the north-west began to form a ridge southward, bringing fine weather to all districts. A cold front moved onto the South Island on the 11th and crossed the country on the 12th, bringing rain to most areas as it passed. The anticyclone which had covered New Zealand earlier in the week remained centred near Norfolk Island during the passage of the front, then again extended south and eastward, forming centres to the east and west of the country during the last 2 days of the week.

15–21 October
A depression developed within a trough close to Tasmania on the 15th and although the anticyclone still covered the North Island a disturbed south-westerly flow spread onto the South Island, with rain in southern and western areas. Rain became much more general as the trough moved onto the country on the 16th, but became restricted to the North Island from the 17th. A large anticyclone developed near Tasmania on the 16th and moved eastward to cover the South Island by the 19th. It continued to lie over New Zealand until the end of the week, with generally fine weather.

22–31 October
As the anticyclone moved off New Zealand on the 22nd a small depression developed in the Tasman Sea with a strong northerly flow onto the country. Rain fell in western areas of both Islands but became widespread as a front crossed the country on the 23rd. A small depression developed near Lord Howe Island and deepened as it moved eastward during the 24th. By the 25th it had moved south to lie over the North Island. Rain fell over most of the North Island and northern South Island on the 24th and 25th. As the depression moved east rain cleared from all except eastern areas of both Islands. An extensive anticyclone developed in the Tasman Sea and as this moved over New Zealand centres developed to the north-west and south-east, with fine weather over the whole country. The centre to the south-east weakened on the 30th and a cold front crossed the South Island, bringing rain to southern and western districts. Fine, warm weather continued in most other districts to the end of the month.

(N.Z. Met. S. Pub. 107) J. S. HICKMAN, Director.

CORRIGENDUM

CLIMATOLOGICAL TABLE FOR NOVEMBER 1981

In the supplement with the above heading published in the New Zealand Gazette, 27 November 1981, No. 142, p. 3617, please read, “Climatological Table for September 1981”.

Price 45c BY AUTHORITY: P. D. HASSELBERG, GOVERNMENT PRINTER, WELLINGTON, NEW ZEALAND—1981 74690B-81